During the Days of the Imams After the Prophet's death...
During the Days of the Imams After the Prophet's death, the Muslims were very much divided on the issue of leadership. This gave birth to the two groups known as the Shi'ahs and the Sunnis. The Shi' ahs believed in the leadership of Imam' Ali bin Abi Talib (a.s.) and the Sunnis believed in the leadership of Abu Bakr. The Shi'ahs lived by the shari'ah by following the Qur’an, and the sunnah of the Prophet and of the imams.
The sunnah, in Shi'ah definition, means "the sayings, deeds and silent approval of the Prophet and the twelve Imams of Ahlul-Bayt." Although the issue of the leadership is beyond the scope of this study, I would like to mention one reason why the Imams of Ahlul-Bayt are preferable as the source of the shari' ah than anyone else. The Muslims of the early days realized the importance of the Prophet's sunnah and started to memorize his sayings known as hadith.
Later generations preserved the saying they had heard from the companions of the Prophet in the books of hadith. Even the actions of the Prophet, observed by his companions, were preserved in writing. But this process of preserving the sunnah of the Prophet was not immune from mistakes and forgery. Many sayings were invented and wrongfully attributed to the Prophet during the early period of the Islamic history, specially during the Umayyid era.
At times, the rulers bribed the companions to fabricate 'hadith' in their favour. At other times, some people invented ahadith for apparently good causes not realizing that they were using wrong means of trying to make people more religious! In this background of the early development of hadith, we must find an authentic and informed source for the sunnah of the Prophet.
When you look at the Muslims of the Prophet's days, you can find no one who was more knowledgeable, informed, reliable and closer to the Prophet than the Ahlul-Bayt, the family of the Prophet: Fatimah, 'Ali and their sons.
After all, it is the Qur' an which testifies to their spiritual purity of the highest form by saying, “'Verily Allah intends to purify you, O Ahlul-Bayt, a thorough purification." (Surah al-Ahzaab, 33:33)[^1] Combine this verse about the Ahlul-Bayt's purity with the following: "It is the holy Qur'an in a preserved tablet, none shall touch it but the purified ones." (Surah al-Waqia, 56:79) The real sense of this verse is that the Qur’an which is "in a preserved tablet" is not accessible to anyone except those who are purified by Him.